Michael Valensa was a son of Emanuel Valensa from London and Sara Gobes from Amsterdam. He married on 6 January 1937 in Amsterdam to Rachel Hartog. Municipal Archive of Amsterdam, archive card of Michael Valensa.
In addition, a Jokos file (number 15061) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.